1. Field of the Invention
This invention relates to display boards and, more particularly, to display boards that may be used to display calendars, removably tacked-on materials, and erasable writings or other markings.
2. Description of Related Art
Dry erase boards and tackable display boards are known. Known boards have a tackable surface, such as cork or fiber and a markable surface, such as melamine, porcelain coated paper, metal, or film. The tackable surface preferably permits a note or display to be attached to the board by a push pin or thumb tack, and preferably the pin or tack may be removed to permit mounting of another note or display. Preferably, markings on the markable surface may be erased with an eraser or wiped with a cloth, to permit other markings to be made on the markable surface. Examples of known dry erase boards and tackable display boards are described in prior art patents, including U.S. Pat. No. 5,527,568 to Boone et al.; U.S. Pat. No. 5,655,323 to Lassoff; U.S. Pat. No. 5,658,635 to Davis et al.; U.S. Pat. No. 5,928,756 to Davis et al.; U.S. Pat. No. 5,948,498 to Bianco; U.S. Pat. No. 5,976,663 to Davis et al.; and U.S. Pat. No. 6,837,715 to Beno.
U.S. Pat. No. 7,260,904 discloses a wall calendar system. The wall calendar system includes several separate sections, including a marker board, a cork board, a paper calendar that is pivotally mounted to the wall calendar system, and a file pouch located on the back of each month of the paper calendar so that the various important papers and business cards may be stored until needed.
The use of dry erase boards as calendars is known. U.S. Pat. No. 6,877,262 describes a perpetual calendar that may include a write-on/wipe-off surface. As noted in that patent, monthly calendars are typically constructed with at least twelve sheets of paper with a single month in one particular year displayed on each sheet. Because the first weekday in each month varies monthly and yearly, each sheet of such a calendar is typically obsolete after the particular month has ended, and a user must display a separate sheet to accurately convey the current month. Likewise, an entire calendar is typically obsolete after the particular year has ended, and a user must discard the entire calendar and replace it with a calendar displaying the accurate configuration of days for the current year.
To counter this problem, several “perpetual calendars” have been invented that allow a single calendar to be reused to display multiple months of multiple years with the appropriate starting weekday. U.S. Pat. No. 1,042,337 to Gorin describes a web or ribbon that is horizontally movable behind an opaque glass front. The web or ribbon includes dates of a month arranged in columns or series so that when it is horizontally displaced, an opening in the glass front exposes the consecutive numbers 1-31 beginning on any weekday of the month. When the month has ended, a button of the last day of the month is pressed, and the web or ribbon is displaced to expose the days of the next month as beginning on the day after the weekday of the button pressed.
U.S. Pat. No. 1,459,236 to Orth describes a perpetual calendar with adjustable knobs for the year, month, and first day of the week for a given month. The knob for the first day of the week operates by horizontally displacing a web, but serves to display dates only for the upper four weeks of a current month. When turned, a fourth knob vertically displaces a second web to display one of twenty-one horizontal lines representing each of the possible date configurations of the last two weeks of a month.
In a conventional paper calendar, a user may write notes directly onto the calendar pages to ensure that events, such as birthdays or meetings, are remembered on the correct day. Because the month page in a conventional calendar is obsolete at the month's end, the page can merely be torn off and thrown away. However, with the perpetual calendars discussed above, because the month grid is reused, any markings on the grid would be carried on to every month, causing confusion and inaccuracy.
Accordingly, U.S. Pat. No. 6,877,262 discloses an erasable perpetual monthly calendar that includes a front panel with a month grid of cells and weekdays permanently displayed on it. The front panel is capable of displaying an accurate number and configuration of any month. At least one surface, which is coupled to and movable behind the front panel, has numbers permanently printed on it and spaced so that when the at least one surface is moved, an accurate number and configuration of days for any month can be displayed through the windows. An at least semi-transparent sheet is coupled to and in front of the front panel and has a write-on/wipe-off surface.
In another embodiment described in U.S. Pat. No. 6,877,262, a perpetual monthly calendar includes a front panel, a first surface with a first number matrix, and a second surface with a second number matrix. The front panel displays a grid of cells with columns representing weekdays and rows representing the upper rows of a calendar and at least one lower row of a calendar. A window is cut out of the front panel in each cell. The first surface is coupled to the front panel and is horizontally movable behind the upper rows and the second surface is coupled to the front panel and is horizontally movable behind the at least one lower row. In this embodiment, the first number matrix is arranged so that by moving the first surface horizontally in relation to the front panel, a plurality of numbers of the first number matrix is visible through a plurality of windows in the upper rows. The first number matrix is also arranged so that the numbers visible through the windows can accurately represent sequential dates of the upper rows of a calendar for a month starting on any weekday. The second number matrix is arranged so that by moving the second surface horizontally in relation to the front panel, at least one of the numbers in the second number matrix is visible through at least one window in the at least one lower row, and can accurately represent sequential dates for the at least one lower row of a calendar for a month beginning on any weekday and an accurate number of days for any month.